Heliostat ->> Hands down the cheapest way to gather the suns energy

Hi all,

I write because I've a normal PV plant on my roof and I'd like to increase its production.

At north of the plant there is a 1m chimney that I'd like to use as reflector, installing a parabolic mirror that, following sun, reflects rays.

My doubts are:

- can heliostat project help me to move parabolic mirror?

- how can I build this parabolic mirror just to reflect sun for a 1mx1m mirror to 6mx4m plant?

Thanks a lot

Alex from Italy

Hi Alex,

you want to take a 1m x 1m mirror an put the light on a 6m to 4m pv plant. That is not a parabolic mirror. Thats a opposit function.

I would say: take a flat mirror and place the light somewhere on your pv plant. Better you take bigger heliostat or more heliostats.

Axel from germany

You may want to be careful putting a mirror on your roof,  I can just see it flying off the roof into your neighbors new car.

I do not know how your PV cells work,  It may need most of the PV's cover equally with the sun to see a increase in the output of the PV cells.

Do your PV cells max out in full sun light?

A few well place heliostats may increase your output.

using the opposite of a parabolic mirror so that a 1m heliostat placed 20 to 100 feet away could hit most of your PV plant. buy three 1 meter mirrors and test it. you are going to need three friends to hold the mirror while you check the plants output.

Hi,

I explained wrong: I need a convex mirror, not a concave one. I'll put the mirror on the chimney that is at north of PV plant, far 1 meter and 1m high.

How can I manage this mirror just to reflect always the sun rays on the panels?

Have I to put the photo-resistance on the panels towards the mirror just to keep it alligned?

I confirm that is very important to have every panels with same light, just to have more output power.

Thanks again

Alex

Hi Alex,

do you need a idea for the mechanics or for the elektronics to move the mirrors?

Have you checked the Photo gallery?

Axel

Hi Axel (I note only now that your name is an anagram of mine :-)

I'm studing the photos and compliments for them, but my doubt, before starting project, is which sensors control step motors, and where they are? I immagine that I must move mirror keeping perpendicular between sun and target, but how?

In photos I note in front of mirrors an object, what is? photocells?

Alex

Hi Alex,

there are different ways to align the mirror:

Photocells on the mirror: Problem the mirror had to be aligned in the half angle between sun and the target. That means a mechanic to move the photocelles. To find at www.redrock.com

Photocells between the mirror and the target: the solution as Leo have choosen for his heliostats. Discription her on the page.

Radio controlled clock: This is my solution. With the actual time the actual sun position is calculated. This is the setpoint to move the steppermotors. It needs two limitswitches to find the homeposition for start counting steps. The Programm will be here, when it ist finished: http://www.mikrocontroller.net/articles/Sonnenfolger_/_Heliostat

Axel

Hi,

putting the sensors in front of mirror we could have problem on target panels.

Besides:

- have I to use a card in my pc to programm chip?

- where is the power circuit to pilot motors?

Thanks

Alex

Hi Aley,

Ok, the sensor in front ofthe mirror makes a small shadow on the target. But the the shadow´s small sizewill be acceptibel.

Progamming the chip dependson the type of chip. Leo is using the PIC controller, I am using the AtmelMega168 controller. This type is programed by an USB-Programmer for aprox. 25€to 40€ . The programming software is freeware.

http://embdev.net   ; is a english speeking forum for the atmelcontroller

http://www.mikrocontroller.net ; is a german speeking forum for the atmelcontroller

The motors are feed by asmall pv-panel with 10W

Axel